We need to develop quite a powerful web application for an investment bank. The bank IT would like us to build it on top of the SharePoint platform
I'll not go into the merits of sharepoint, but suffice it to say that I have been developing in sharepoint since it was known as "digital dashboard" - it was just a javascript-encrusted today page for outlook. With respect to its .NET incarnations, it has taken me about 3 years to become what some might call "expert" on SharePoint 2007/MOSS.
First up, let me give you some warnings concerning the politics of these kind of jobs. As a contractor, ALL of my jobs over the last 6 years - covering shaerpoint 2003 and 2007 - WITHOUT fail, have been getting about me on site with a client who has demanded sharepoint, and a development shop with decent ASP.NET developers who have become hopelessly lost and more than likely have blown 95% of the budget on the last 5% of the project because they have embarked on writing custom extensions to the platform without fully understanding the product.
If clients, and the shops who service them, spent more time understand the product and studied it to see how they could change/streamline their business processes & requirements slightly to suit sharepoint instead of being rigid in their specs (that were ALWAYS written with next to zero real experience of the platform) and deciding to get custom development done, then more sharepoint projects would be delivered on time and on budget. Sadly, this is not the case.
So, number one: SharePoint 2007 is an excellent product, but please, for the love of jeebus, find yourselves some top gun sharepoint developers who really understands the product before you embark on this journey. If you don't, you will all go down in flames.
-Oisin